Material Studio (geometry optimization)

[Vellaboy89]

Hi. I am using Material Studio (MS) version 4.3 (yeah I know it's old but that's all I've got) and I have been trying to calculate this energy of a specific compound (N,N-dimethylformamide). I've learned that there are 3 ways on how to calculate energy using MS; Forcite, Dmol3 and Minimizer functions.

However, using Forcite and Minimizer gives me a positive total energy for the compound, which is kind of weird because a positive energy means that that the compound is unstable, am I right? So I tried using Dmol3, it gives me negative energy (yeay!), and afterwards I tried minimizing this same compound using Minimizer, then bamm, it becomes positive again.

My question is, why would this happen? Which function is actually better for calculating energies / geometry optimization? Or is there any chemistry-related explanations about all this?

Thanks.

 

[Vellaboy89]

FYI, I got the structure of the compound directly from Cambridge Crystallographic Database.

 

[MarkJW]

I think you should be in the Chemistry forum. Material Studio is a powerful molecular modeling software, and pretty specialized. You may have a hard time getting much help even on this forum. Contact your Biovia (formerly Accelrys) office for technical assistance.